* Senior club appearances and goals counted for the domestic league only and correct as of 28 August 2016 (UTC).

‡ National team caps and goals correct as of 26 June 2016

Thomas Vermaelen (Dutch pronunciation:[ˈtoːmɑs fərˈmaːlə(n)];[3] born 14 November 1985) is a Belgian professional footballer who plays as a centre-back for Italian club Roma on loan from Barcelona. He also plays for the Belgium national team. Being left-footed, he usually plays as a left-sided centre-back and can play at left-back as well.[4] His key attributes include aerial ability, leadership skills, and his quickness with the ball at his feet. He is also known for his goalscoring ability as a defender.

Vermaelen joined Arsenal from Ajax for an initial fee of €10 million (rising to €12 million) on 19 June 2009, signing a four-year contract.[7][8] After Kolo Touré surrendered the number 5 jersey to him upon joining Manchester City,[9] Vermaelen, with William Gallas, formed Arsenal's central defence pairing. Vermaelen made his Premier League debut on 15 August 2009 in a 1–6 away win against Everton, and scored in the 37th minute.[10] He became the 84th Arsenal player to score in their debut.[11] He then scored a brace against Wigan Athletic in a 4–0 victory.[12]

Arsenal fans voted him as their Player of the Month twice in a row on Arsenal.com,[13][14] and affectionately nicknamed him the "Verminator".[4] He scored an own goal, however, in a home match against Chelsea when a cross came in from Ashley Cole. The game finished 0–3 to Chelsea at the Emirates Stadium.[15]

Vermaelen became notable for being a goal-scoring defender due to his spectacular 25-yard, left-footed goal against Blackburn Rovers and many headed goals during the first half of Arsenal's 2009–10 season.[16] In recognition of his contributions, he was nominated for the Belgian Sportsman of the Year award[17] and was also included in the PFA Team of the Season.[18] Vermaelen finished the season with 45 games and eight goals in all competitions under his belt.

He had a new injury setback when manager Arsène Wenger reported that the Achilles tendon problem would keep him out of action until 2011.[21] On 17 March 2011, Wenger confirmed that Vermaelen would miss the remainder of the season with a new injury setback,[22] but on 26 April, Vermaelen played 90 minutes in his first competitive game after eight months in a reserves game against Manchester United at Old Trafford on 28 April. On 8 May, he was included in Arsenal's 18-man squad travelling to Stoke City at the Britannia Stadium; Vermaelen, however, was an unused substitute, but on 15 May, he finally returned in Arsenal's 2–1 defeat to Aston Villa and played the full 90 minutes.

Following Cesc Fàbregas' transfer to Barcelona in August 2011, Vermaelen was named vice-captain of Arsenal, with Robin van Persie named captain.[23] On 6 September 2011, Vermaelen had treatment on his Achilles tendon which ruled him out for six weeks. On 18 October 2011, he signed a contract extension to keep him at the club for an additional four years. He made his long-awaited return against Bolton Wanderers in the fourth round of the League Cup, where he captained the side to a 2–1 victory at the Emirates Stadium. He suffered a suspected calf injury in the 84th minute, but to Arsenal's relief, he stated in the post-match interview it was just a cramp. On 1 November, Vermaelen started his first UEFA Champions League game in three months against Marseille and played a key role in helping keep a clean sheet for the Gunners in which the game ended 0–0.

Vermaelen scored Arsenal's second goal in their 3–0 win over West Bromwich Albion on 5 November. He also featured in the 1–1 draw with Fulham on 26 November, when he scored a 65th minute own-goal but salvaged a point with an 82nd-minute equaliser for Arsenal. On 3 December, Vermaelen scored the second goal against Wigan to win the match 4–0.[24] On 12 March 2012, Vermaelen scored the winner in the 95th minute against Newcastle United. He had run the entire length of the pitch to score a half-volley from Theo Walcott's cross. In the following game, he converted a Robin van Persie corner, heading home Arsenal's only goal in a 0–1 victory over Everton at Goodison Park. On 16 April 2012, he headed home a Tomáš Rosický cross against Wigan to reduce the deficit to 1–2, with Wigan having taken a two-goal lead at the Emirates. The scoreline, however, finished the same. Manager Arsène Wenger has called him a defensive rock and his partnership with Laurent Koscielny is strong, enabling Arsenal to build from the back.

Vermaelen's performances forced Arsène Wenger to drop him for the pivotal Champions League game against Bayern Munich at the Allianz Arena. Arsenal won 0–2, although it was not enough to progress to the next round through aggregate, but they were the first team to prevent Bayern from scoring that season, thanks to an assured performance from the defence and reserve goalkeeper Łukasz Fabiański.[27]Per Mertesacker and Laurent Koscielny continued to partner each other at centre-back for the following games, until the former's red card against West Brom at The Hawthorns on 6 April 2013 gave Vermaelen a chance to reestablish himself in the team. Arsenal held on for a 1–2 win. Due to Mertesacker's suspension, Vermaelen partnered Koscielny for the game against Norwich City on 13 April, with Arsenal winning 3–1.

On 9 August 2014, Arsenal accepted a £15 million offer from Barcelona for Vermaelen.[28] The next day, he completed his move after signing a five-year contract.[29][30] Vermaelen was plagued with injuries since his transfer; he was thought to be ready for Barcelona's game against APOEL in the Champions League, but was taken out of the squad. He underwent surgery on 2 December 2014 for a recurring hamstring injury, and was expected back in four-to-six months.[31] After being an unused substitute in a 2–0 win over Real Sociedad two weeks earlier, Vermaelen started on his debut for Barcelona on 23 May 2015 in the final La Liga match of the season against Deportivo de La Coruña in which he played for 63 minutes before being substituted for Douglas in a 2–2 draw at the Camp Nou.

On 13 May 2014, Vermaelen was named in Belgium's squad for the 2014 World Cup.[35] After spending Belgium's first match of the tournament, a 2–1 win against Algeria, on the substitutes' bench,[36] Vermaelen was chosen to start in the second match against Russia, replacing former Ajax teammate Jan Vertonghen at left-back.[37] After 31 minutes, however, Vermaelen was taken off with an injury and replaced by Vertonghen.[37]